148 - Bile Acid Metabolism: a potential indicator for red blood cell transfusion in preterm infants

Poster Number: 148
Publication Number: 148.22

Sol Rivera, Molecular Determinants Center and Core, Petersburg, FL, United States; Ravi M. Patel, Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States; Joshua Lukemire, Emory University, Atlanta, GA, United States; Neeta Shenvi, Emory University, Atlanta, GA, United States; Connie Arthur, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; Sean Stowell, Brigham and Women's Hospital/Harvard Medical School, Boston, MA, United States; Kirk A. Easley, Emory University, Atlanta, GA, United States; Ying Guo, Emory University, Atlanta, GA, United States; Cassandra Josephson, Johns Hopkins University School of Medicine, St. Petersburg, FL, United States; David Graham, Johns Hopkins University School of Medicine, Germantown, MD, United States

Background: Red blood cell (RBC) transfusion is a common life-saving intervention in preterm infants with up to 90% of extremely low birth weight infants (ELBW, < 1,000g) and 60% of very low birth weight infants (VLBW, < 1,500g) receiving at least 1 RBC transfusion. RBC transfusion continues to have inherent risks including metabolic, immunologic and infectious complications as well as play a role in risk of bronchopulmonary dysplasia, retinopathy of prematurity, and necrotizing enterocolitis. RBC transfusion triggers guidelines remain a subject of debate and the most comprehensive studies to date rely predominantly on hemoglobin levels. 

Objective: To determine if there may be preterm infant metabolic indicators associated with RBC transfusion.

Design/Methods: The study was designed as a 1:2 case control, nested in a birth cohort study, comparing those preterm infants who were transfused versus those who were not transfused RBCs.  All infants were VLBW. Residual whole blood samples were obtained during each infant’s third week of life despite their gestational age at birth. Pre-transfusion samples were tested for the transfused infant group. Five microliter aliquots were extracted and analyzed in triplicate using liquid chromatography (LC) C18 column with negative electrospray ionization and Fourier transform high-resolution mass spectrometry (MS). LC-MS data was processed with Progenesis QI software followed by CV filtering. Statistical analysis and data modeling were performed using MetaboAnalyst software. T-Test was used as statistical test. FDR: 0.05 was used to correct by multiple comparison.

Results:

Control preterm infants n=18 (9 females, 9 males) who did not receive RBC transfusion during their hospitalization (mean weight 1000 g, 44% African American, 33% White Non-Hispanic, 11% White Hispanic, 11% Asian) were compared to n=9 preterm infants, (6 females, 3 males), who received RBC transfusion (mean weight 833g, 66% African American, 33% Caucasian). After quality control criterion were added n=2,225 features passed. Putative metabolites were associated with RBC transfusion including a bile acid and fatty acid ester (Figure 1; all p values were < 0.001).

Conclusion(s):

This preliminary study suggests that bile-acids may putatively be associated with individuals that go on to receive RBC transfusion. These results represent only one analytical chemistry method used to date that is biased towards lipid metabolism. Bile acid metabolism is known to be impaired in VLBW infants, but has not yet received attention as a potential indicator for RBC transfusion despite their critical role in metabolism.